Blast furnace lining removing machine



1967 A. GRANT BLAST FURNACE LINING REMOVING MACHINE 1O heets-$heet 1 Filed Aug. 8, 1966 INVENTOR. LOUIS A. GRANT aw al Fig.4.

'5 ATTORNEY L. A. GRANT Oct. 10, 1967 BLAST FURNACE LINING REMOVING MACHINE l0 Sheets-Sheet 2 Filed Aug. 8, 1966 INVENTOR LOUIS A.GRANT his ATTORNEY 0a. 10, 1967 L. A. GRANT BLAST FURNACE LINING REMOVING MACHINE 1O Sheets-Sheet 3 Filed Aug. 8, 1966 INVENTOR.

LOUIS A. GRANT Oct. 10, 1967 L. A. GRANT 3,346,300

BLAST FURNACE LINING REMOVING MACHINE Filed Aug. 8, 1966 10 Sheets-Sheet 4 RESERVOIR 527 TOOL CYLINDER I- l8 AEBJQ QM CYLINDER INVENTOR. LOUIS A. GRANT his ATTORNEY Oct. 10, 1967 1.. A. GRANT 3,346,300

BLAST FURNACE LINING REMOVING MACHINE Filed Aug. 8, 1966 10 Sheets-Sheet 6 INVENTOR. LOUIS A. GRANT his ATTORNEY Oct. 10, 1967 1.. A. GRANT 3,346,300

BLAST FURNACE LINING REMOVING MACHINE Filed Aug. 8, 1966 l0 Sheets-Sheet 6 INVENTOR.

LOUIS A. GRANT his ATTORNEY Oct. 10, 1967 1.. A. GRANT BLAST FURNACE LINING REMOVING MACHINE 1O Sheets-Sheet 7 Filed Aug. 8, 1966 INVENTOR. LOUIS A. GRANT Q ZQ AZ his ATTORNEY Oct. 10, 1967 L. A. GRANT BLAST FURNACE LINING REMOVING MACHINE 1O Sheets-Sheet 8 Filed Aug. 8, 1966 L INVENTOR.

- Louis A. Grant 2 7: 5? A w 444' M4513 L. A. GRANT Oct. 10, 1967 BLAST FURNACE LINING REMOVING MACHINE 1O Sheets-Sheet 9 Filed Aug. 8, 1966 INVENTOR. Louis A. Grant BY 7%? %M United States Patent 3,346,300 BLAST FURNACE LINING REMOVING MACHINE Louis A. Grant, 7 886 Saltsburg Road, Pittsburgh, Pa. 15239 Filed Aug. 8, 1966, Ser. No. 573,758 Claims. (Cl. 299-70) ABSTRACT OF THE DISCLOSURE The disclosure is directed to the combination of a platform supported within a blast furnace having a brick 11ning and a vehicle having a demolition tool mounted on a telescopic boom, the boom being carried by a turntable on the vehicle. The platform is suspendable within the furnace and includes means for engaging the furnace wall to anchor the platform within the furnace at preselected heights. The vehicle is supported by the platform Within the furnace and the adjustable boom positions the demolition tool to demolish the brick lining of the furnace. The mounting of the tool on the boom includes adjustment means whereby a substantial portion of the furnace lining may be removed from a single fixed position of the platform within the furnace.

The present invention is a continuation-in-part of my application Ser. No. 326,002, filed Nov. 26, 1963, entitled, Blast Furnace Lining Removing Machine.

This invention relates to a demolition method and apparatus, and more particularly to such apparatus for very rapidly and automatically skulling or removing brickwork or other masonry forming the inner lining of blast furnances or similar structures.

Heretofore, the conventional way of removing the lining of a blast furnace has been by using a crew of men carrying air hammers or drills and having the men operate these tools individually while they are stationed inside the furnace. This has been a very time consuming and expensive operation in view of the large number of man-hours required for completely removing the lining. Not only has the labor cost been high, but in view of the long time required for manually performing this operation, there has been considerable loss of production of steel as a consequence of this down-time which represents an even greater loss.

An object of the present invention is to provide a novel method and apparatus for overcoming the above-named disadvantages of conventional methods and apparatus for skulling or removing the inner brick lining of a blast furnace, or similar structures, such as glass making tanks, recuperators and similar large structures or vessels having an inner lining of firebrick requiring occasional removal and replacement.

Another object of the present invention is to provide a novel, self-propelled demolition machine of such construction and size, that it can be driven to and progressively lowered into a blast furnace or similar structure, which machine has sufiicient flexibility in operation of the drillsupporting boom so at to be readily operated for rapidly removing the brick lining in only a small fraction of the time normally required, thereby saving labor costs as well as minimizing loss in the production of steel.

A further object of the invention is to provide a novel method and apparatus involving the use of two selfpropelled skulling machines disposed closely on a platform with drilling booms extending diametrically oppositely within the interior of a blast furnace, which platform is progressively lowered and its extensible legs expanded to conform to the progressive changes in interior dimension of the blast furnace so as to rapidly skull the inner 3,346,300 Patented Oct. 10, 1967 lining completely as the platform descends within the furnace.

Other objects of the invention include the provision of a novel tool cradle for use with the demolition apparatus to impart a greater range of angular adjustment to a tool or implement carried by the apparatus, the provision of novel independent drive systems for the crawlers of the apparatus, and the provision of a novel boom structure for use with the demolition apparatus to provide a greater working area therefor at a given position of the apparatus.

These and other objects, features and advantages of the invention will be elaborated upon in the following descrip tion thereof taken with the accompanying drawings wherein;

FIGURE 1 is a top plan view showing a pair of drilling or skulling machines supported on a platform within the interior of a blast furnace or similar structure, which platform and furnace are shown in chain outline;

FIGURE 2 is a top plan view of one of the machines shown in FIGURE 1 and illustrating in dash outline different positions to which the boom is movable horizontallly;

FIGURE 3 is a side elevational view of the machine as shown in FIGURE 2 and illustrating in dash outline different positions to which the boom can be moved along a vertical are together with the pivotally attached toolsupporting cradle;

FIGURE 4 is a front elevational view of the machine shown in FIGURE 2;

FIGURES 4A and 4B are enlarged, cross-sectional views of the boom taken respectively along lines IVA- IVA and IVB-IVB of FIGURE 3;

FIGURE 5 is a schematic circuit arrangement of the hydraulic system utilized in machines shown in FIGURES 14 and in FIGURES 15-18;

FIGURES 6 and 7 are partial, top plan and side elevational views, respectively, of a conventional type boom, such as used on a Gradall earth excavating machine and including a novel tool cradle embodying my present invention for supporting a demolition tool and its rod or hit in a manner so as to minimize breakage of the bit;

FIGURE 8 is a side elevational view similar to FIG- URE 7 but showing the cradle after it has been removed and reversed, that is, flopped over degrees, in order to enable the cradle and tool to be moved to a greater angle of elevation;

FIGURE 9 is a partial, side elevational view showing my improved boom having mounted thereon a tool cradle similar to that shown in FIGURES 6, 7 and 8 and including additional novel drive mechanisms for the cradle;

FIGURE 10 is an enlarged partial, cross-sectional view taken along line X-X of FIGURE 9 and showing my novel drive mechanism for rotating the tool-supporting cradle throughout an angle of 360 degrees;

FIGURE 11 is a cross-sectional view of the drive mechanism as shown in FIGURE 10 and taken along reference line XIXI thereof;

FIGURE 12 is a top plan view of a platform for supporting the above described self-propelled skulling apparatus, which platform is provided with hydraulically extensible legs for anchoring to inner wall portions of varying diameter as the platform is progressively lowered into the blast furnace or similar structure shown in chain outline;

FIGURE 13 is a partial top plan view of another form of the apparatus-supporting platform;

FIGURE 14 is an enlarged, cross-sectional view of the hydraulic means shown in FIGURE 12 for extending the legs from the platform;

FIGURE 15 is a side elevational view, partially sectioned and broken away, of another form of the demolition machine of the invention;

FIGURE 16 is an enlarged, partial cross-sectional view of the apparatus shown in FIGURE 15 and taken along reference line XVIXVI thereof;

FIGURE 17 is an enlarged, partial, rear elevational view of the apparatus shown in FIGURE 15 and taken generally along reference line XVIIXVII thereof; and

FIGURE 18 is an enlarged, partial, top plan view of the apparatus as shown in FIGURE 17 and taken generally along reference line XVIII-XVIII of FIGURE 15.

Referring more particularly to FIGURE 1 of the drawings, numeral 1 generally denotes a blast furnace or similar structure having an inner lining of fire bricks or the like to be removed, which furnace and lining are shown in chain outline. Numeral 2 generally denotes a self-propelled, skulling or demolition vehicle of novel construction and embodying the principles of the present invention. Two of these vehicles are shown, disposed in side-by-side, but opposite relationship with respect to the directions in which the booms are extended.

The respective skulling vehicles 2 are crawler-mounted for propelling by tractor treads 3, or, in some cases, are mounted on wheels (not shown). Each machine or vehicle has a body or rotatable platform 4 for supporting a boom 5, and has an air-cooled gas engine 6 which drives a hydraulic pump 9 which is fed by a reservoir 8 which supplies hydraulic liquid to the valve manifold 10 (see FIGURE As shown more clearly in FIGURE 4, on the base of machine 2 is mounted gear reducer 14 which drives pinion or driving gear 13 which rotates a gear 12 and thereby rotates the body 4 about a vertical axis and through an angle of 360 degrees.

In view of the fact that booms of conventional triangular cross-section are insufficiently strong for supporting a boom extension on which a drill is mounted when used in a furnace, a special construction of square or rectangular cross-section has been devised which embodies novel and unique features, one form of which is shown in FIGURES 4A and 4B. The boom 5 is shown as including a stationary boom section 11 from which extends a telescoping boom section 15 (see FIGURE 1) which may be extended longitudinally by varying amounts as rollers 24, which are disposed at an angle as shown, roll along pipes or other suitably shaped rib members 23 disposed within the four corners of the stationary boom 11. The rollers are held in place within a frame or boom 15 which includes pipes 25 or other suitably shaped rib members at the corners.

It will be readily apparent that the base or stationary boom section 11 can be alternatively inserted into the telescoping boom section 15 which in the alternative arrangement is made correspondingly larger in cross-section rather than smaller as shown. Other antifriction means such as shown in FIGURES 15 and 16 and described below, can be substituted for the rollers 24, 26 and pipes or rails 23, 25.

FIGURE 4A shows a rear roller assembly for guiding the telescoping boom, in which the rollers 24 are disposed at an angle, and FIGURE 4B shows a front roller assembly for guiding the telescoping boom, in which assemblythe rollers 26 are disposed inparallel planes. This structure provides a very strongly supported and guided extensible boom 15 which may carry considerable overhanging weight and withstand considerable lateral drilling forces and shock loading.

FIGURE 2 shows two different positions, 1211 and 12b in dash outline, to which the boom may be moved along an arcuate path in a horizontal plane by rotation of gears 12 and 13 by gear reducer 14. Of course, the boom may be moved to a much greater extent, that is, through an arc of 360 degrees about a vertical axis, if desired. As shown more clearly in FIGURES 2 and 3, the telescoping boom section 15 is selectively moved or extended outwardly of the base boom section 11 by means of a hydraulic cylinder 16 and in so doing is;

. 4- guided by rollers 26. Rigidly secured to the end portion of the telescoping boom 15 is a bracket 20 having pivotally mounted, at 20a, a cradle or support 17 for an air hammer or other demolition tool 19a which drives a drill rod or other suitable bit 19. The chain outline shows a different position of the cradle 17 achieved by operation ofhydraulic cylinder 18, which effects pivotal movement, in a vertical plane, of cradle 17 by virtue of attachment of the piston rod to bracket 17a of the cradle.

The entire boom may be selectively moved to widely different elevational angles along a vertical are, such as indicated by dash lines 21a and 21b, as a consequence of operation of hydraulic cylinder 21. Thus, the boom may be rotated throughout 360 degrees in a horizontal plane, and it may be moved about 90 degrees in a vertical plane and the cradle 17 may be pivotally moved about pivot 20a, so to provide considerably greater versatility of movement of the drill 19 to different positions than heretofore possible.

FIGURES 6 and 7 show an improved cradle 65 having transversely extending clamps 66 and 67, or other suitable clamping means, for clampingthe air hammer 69 in place. The cradle has an improved supporting hearing 70 for directly supporting the drill rod 19 so as to minimize the tendency of breakage of such rod during use. Numeral 60 denotes an extensible boom of triangular cross section and of well known construction, such as used on Gradall earth moving machines sold by Warner Swasey Co. of Cleveland, Ohio, and including a hydraulically operated and reciprocable rod 63 pivotally connected at 64 by means of a pin so as to enable pivotal movement of the cradle 65 about hearings or rods 62 which are encircled by clamps 61, in a well known man? ner on Gradall machines.

A highly important feature of the present invention resides in the alternate use of either registering holes 64 or 64a of the cradle 65 to form a pivotal connection with rod 63. More specifically, when it is desired to raise the cradle 65 and drill to the maximum vertical angle, the cradle 65 is removed by first unclamping clamps 61. Then, the cradle is flopped over 180 degrees and the rod 63 is reconnected to hole 64a, as shown in FIGURE 8, instead of the former hole 64, whereby the drill and supporting cradle may be moved vertically upwardly to a greater extent, as shown in FIGURE 8.

FIGURES 9, 10 and 11 show the hydraulic operating means and motor drive provided at the outer end of tele scoping boom section 15. A hydraulic motor 78'rotates a revolving support or bracket 85 for the cradle 17 through an angle of 360 degrees by virtue of a planetary gear drive denoted generally by numeral 74. Housings 75 and-88 are bolted together by bolts 89 and the housing is bolted by bolts 77 to the telescoping boom section 15. The motor drive shaft 79 rotates a spur gear 80 which drives a planetary gear 81 rigidly secured to a driven shaft 84 which rotates within bearings 86 and 87, which are clamped in place by a cover 90.

In operation, hydraulic motor 78 drives the cradle support and tool'cradle 17 about their longitudinal axes through an angle of 360 degrees. In addition, by virtue of operation of hydraulic cylinder 18a, the cradle 17 is pivotally rotated about its pivotal shaft mounted on a bracket extending from support 85.

FIGURES 12 and 14 show a demolition'apparatus supporting a platform 94 of polygonal shape having a plurality of integrally connected tubes 98 which extend outwardly in degrees, 180 degrees, 270 degrees and 360 degrees relationship. Extending outwardly of each tube 98 is an extension rod 99 terminating in a pad or anchor element 100 which frictionally engages the inner surface of the brick lining interiorly of the furnace. As shown more clearly in FIGURE 14, each rod 99 may be selectively extended by introducing hydraulic liquid at inlet so as to push piston head 101 and ring 102 longitudinally along the inner surface of the tube 98 until a stop 104 is reached.

FIGURE 13 shows a modification of the platform as being made up of a plurality of frames 95, 96 and 97 disposed in angular relationship as shown.

FIGURE 5 schematically illustrates the complete hydraulic system and more clearly illustrates the operation of the various parts of the machine. In this example, an air cooled gas engine 6 drives a hydraulic pump 9 which is fed by reservoir 8 through pipes 30, 31 and 32. The pump 9 includes units 9a, 9b and 9c. Hydraulic liquid flows through pipes 33, 43, 53 to valve manifold 10 comprising units 34, 44 and 54. From the manifold 10, lines 51 and 52 feed hydraulic fluid to the tool cylinder 18. Similarly, a pair of lines extending from the manifold 10 supplies hydraulic fluid to the inner boom cylinder 16, and another pair of lines 40, 42 supplies fluid under pressure to the main boom cylinder 21. Also supplied by valve manifold 10 are a plurality of supply lines 35 and return lines 57 feeding a hydraulic swivel 37. This swivel is connected by supply lines 38 and return line 39, to the trac tor tread drive motor 22 and another pair of lines 46 and 48 are connected to a hydraulic motor 47 which drives gear reducer 14 and driving gear 13.

A second section 1% of the valve manifold is operated by the various control levers 36, 56, 41 as well as pedals 45 and 50. Operation of control levers 36 supplies hydraulic fluid under pressure to drive hydraulic motors 22 which, in turn, furnish forward and reverse motions to the tracks or crawlers 3, respectively of the machine. In like manner, controls 41 and 56 furnish hydraulic fluid under pressure to activate the boom travel, both vertically and horizontally. The control pedals 45 and 50 furnish power to operate tool cylinder 18 and to drive hydraulic motor 47 which, in turn, drives gear reducer 14 which rotates the turntable.

In operation, when it is desired to remove the interior brick lining of a furnace of the character described a pair of vehicles are driven onto platform 94 and positioned side-by-side, in the manner shown in FIGURE 1, within the interior of the furnace. The platform is suspended by means of cables (not shown) secured to peripherally spaced portions, and progressively lowered into the furnace to different vertical positions at which time the legs 99 of the platform are extended outwardly, as shown FIGURE 12, and anchored to the furnace walls. The machines will then operate in tandem and drill inner wall portions of the lining spaced about 180 degrees apart. In so doing, the booms 11 of the respective machines will be progressively pivoted about vertical axes to different angular positions while desirably still maintaining the 180 degrees relationship, approximately, between drills.

When it is desired to tilt boom 11 upwardly or downwardly, controls 41 and 56 are operated so as to control the liquid in the main boom cylinder 21 to cause such lifting or lowering, as shown in FIGURE 3. To tilt the tool cradle 17 relative to bracket 20, cylinder 18 is operated by suitable control levers 45, 50. To extend or retract extension boom 15, the inner boom cylinder 16 is operated by control levers 36.

Then, as the interior diameter of the furnace increases or decreases, extension rods 99 are correspondingly extended or retracted so that pads 100 are securely anchored against the inner surface of the brick lining surface before drilling at a new elevation.

While it is advantageous to have each machine mounted on wheels or tractors so that the machine may be easily driven from place to place, in certain applications, it is contemplated that the crawler tractor portion 3 can be omitted and that the chassis or supporting frame of the machine can be mounted directly on the supporting platform 94. Also, if the furnace has bricks at a very low depth, that cannot be reached otherwise, the crawler mounting 3 may be omitted or removed at the site. It is also contemplated that the platform 4 including boom 5 can be rotatably mounted directly on the supporting platform 94.

In some instances, the two booms instead of one and extending in opposite directions may be mounted on a single body or rotatable platform 4 on a machine, which is either mounted on ,a tractor or wheels, or is mounted directly on the platform 94.

Referring now to FIGURES 15-18 of the drawings, furnace delining or other demolition apparatus similar to that described above in connection with FIGURES L4 of the drawings is illustrated. In the arrangement of FIGURES 15-18, however, means are provided for producing a compact boom assembly 5' by eliminating the roller and rail assemblies shown more particularly in FIGURES 4A and 4B of the darwings. Additionally, means are provided for mounting the boom assembly 5 in a number of operative positions relative to the turntable 4' so that the demolition tool 17 or other implement can be moved over a much larger work area without moving the crawlers 3'. This is particularly advantageous where the aforementioned work area is on a level above or below the floor or base level on which the crawlers 3 rest, and it is not possible to move the crawlers between such levels, denoted for example by chain outline 110. This additional freedom of movement that can be imparted to the boom assembly 5' also permits the demolition tool or other implement to be operated very closely to or even between the crawlers 3' as designated by chain outline 112. A unique drive arrangement, as described hereinafter in connection with FIG URES l7 and 18, is coupled to the crawlers 3' to permit turning or otherwise maneuvering the machine within a more confined space.

Referring now to FIGURES l5 and 16 in greater detail, novel means are provided for mounting the boom structure 5 in a number of spaced positions extending longitudinally of pivot cradle 114 which supports the boom structure 5' on the turntable 4'. Such means include a plurality of spaced trunnions 116 or equivalent pivot means positioned along a portion of the length of the main boom section 11. Each of the trunnions 116 are arranged for clamping engagement by hold-down brackets 118 so that the boom structure 5 can be pivotally mounted on the pivot cradle 114 at any of the positions represented by the locations respectively of the trunnions 116, in the manner better shown in FIGURE 16. Thus, when the turntable 4 is in the rotative position thereof shown in FIGURE 15, the boom assembly 5' can be moved forwardly or rearwardly of the crawlers 3' as denoted by partial chain outlines 120 of the boom assembly 5'.

In order to impart a greater range of angular displacement of the boom assembly 5 through perpendicular are relative to the turntable 4 the actuating cylinder 21 is disposed for connection to the adjacent undersurface of the base boom section 11' at a position rearwardly of the pivot bracket 118, relative to the demolition tool 17. With this arrangement of the invention the angular displacement of the boom assembly 5 is limited substantially only by the presence of the turntable 4 as denoted by the chain outlines 112 and 122 respectively. The distal end of piston rod 124 of the cylinder 21' is secured to clevis 126, which is secured at a suitable one of a number of clevis positions spaced along the undersurface of the base boom section 11' and corresponding respectively to but not in vertical registration with the trunnions 116. Those clevis positions 128 which are not in use are desirably left vacant so as not to interfere with the cylinder 21 or so as not to engage turntable 4, as the case may be, when the boom 5' is pivoted about the associated one of its trunnions 116. When the boom assembly 5' is thus pivoted throughout its aforementioned vertical arc the clevis positions not in use are designated by the chain outlines 128 of FIGURE 5 and desirable suitable mounting bolt apertures 130 or other suitable connection means are provided at the undersurface of the base boom section 11' at each of the clevis positions 126 or 128, as better shown-in FIGURE 16.

As described previously in connection with FIGURE 3 and. related figures the inner boom section 15' is telescoped within the outer section 11 by means of a suitable piston and cylinder arrangement 16 one end of which is mounted within the outer boom section 11'. Although the cross sectional configuration of the inner and outer boom sections 15', '11 are shown in this example as being square (FIGURE 16), it will be understood that any suitable configuration can be substituted depending upon the application of the invention. For example, the boom sections 11, 15 can be of interfitting circular configuration.

In the arrangement of FIGURES 1518, however, a more compact boom assembly can be constructed inasmuch as the annular space between the boom sections 11, 15 (FIGURE 3) is eliminated together with the roller and rail arrangements 23, 26 (FIGURES 4A and 4B). A pair of elongated relatively thin wearing strips 132 are secured to each side 134 of the inner boo-m section 15 as better shown in FIGURE 16. With this arrangement each pair of wearing strips 132 are fitted relatively closely against the inner surface of the associated side 136 of the base boom section 11. Sufficient clearance, however, is provided between the aforementioned inner surfaces of the base boom section 11' and the pairs of wearing strips 132 to prevent binding under loads applied to the demolition tool 17' or other implement during the operation of the apparatus. As better shown in FIG- URE 15 each of the wearing strips 132 desirably extends substantially along the entire length of the inner boom section 15. Alternatively, the wearing strips 132 can be secured to the inner surfaces of sides 136 of the base boom section 11 for engagement with inner boom section sides 134.

Referring now to FIGURES 17 and 18 a unique driving arrangement is illustrated therein for imparting independent motions respectively to the crawlers 3'. The outer ends of independent drive shafts 138 are secured to pinions respectively of conventional gear reduction units (not shown) mounted respectively in driving relation on the conventional crawlers 3'. The drive shafts 138 extend through tubular shaft housings 140 respectively which are secured at their outer ends to the aforementioned gear reduction units and at their inner ends to gear casings 142 and 144 respectively. The gear casings 142, 144 contain additional reduction units, each of which includes in this example a bevel ring gear 146, and other components described below, for the independent drives respectively.

The drive for each crawler 3' further includes a hydraulic motor 22', which is energized by means of the hydraulic system of FIGURE 5. The output shafts 148 of each hydraulic motor 22' extends through a bearing housing 150 couple-d to the associated gear casing 142 or 144 and containing pre-loaded thrust and radial roller bearings 152. To the outer end of each motor output shaft 148 is secured a bevel pinion 154 which is enmeshed with the aforementioned ring gear 146. The ring gear 146 is mounted on a gear carrier 156 which in turn is splined to the inner end of the associated drive shaft 138, as denoted by reference character 158. The enrneshment of the pinion 154 and ring gear 146 is maintained by means of an annular wear strip or thrust ring bearing 160.

A radial bearing 162 is provided for the adjacent inner end portion of each drive shaft 138 and radial bearing for the ring gear carrier 156 is provided by hearing sleeve 164. The bearing sleeve 164 engages a cylindrical projection 166 of the gear carrier 156 for this purpose. The sleeve bearing 164 is supported on a bearing holder 168 which is bolted or otherwise secured to the adjacent inner surface of the associated gear casing 142 or 144. Any inward thrust forces denoted by arrow 170, which may be imparted to the output shafts 138, particularly if the afore-.

mentioned conventional gear reduction units contain gears with helical teeth or the like, are also absorbed by the sleeve bearing 164 and the bearing holder 168. In furtherance of this purpose the sleeve bearing 164 and, if desired, the supporting cylindrical projection 172 of the bearing holder 168 engage a shoulder 174 formed on the ring gear carrier 156 at the base of its cylindrical projection 166. With this arrangement the bearing holder and sleeve bearing provide both radial and thrust bearing for the gear carrier 156 and associated parts.

If desired the gear casings 142, 144 can be Welded together (not shown) at their points of engagement in order to improve the structural stability of the independent drive mechanisms. In furtherance of this same purpose, as better shown in FIGURE 18 the gear casings 142, 144 in this example are welded or otherwise secured respectively to a pair of mounting brackets 176, 178 which in turn are bolted or otherwise secured to crossbrace 180 forming part of the chassis structure for the machine.

Thus it will be seen that I have provided a novel method and apparatus for easily and quickly removing an inner brick lining of a blast furnace, open hearth furnace, recuperator or soaking pit or similar structures or containers of large size having an interior brick lining that must be removed and replaced from time to time, which method and apparatus will remove the brick lining in a very small fraction of the time normally required, therefore, effecting tremendous savings in labor cost as well as greatly minimizing stoppage in production and its attendant losses which are even greater than labor costs; furthermore, I have provided a novel machine in the form of a vehicle which is so constructed that the boom mounted thereon is highly maneuverable so that the demolition tool can be moved to practically any position within the furnace, that is, throughout an angle of 360 degrees in a horizontal plane and throughout a substantial height so as to effectively remove a large number of bricks in the lining at a given elevation of the machine; furthermore, I have provided a novel support or cradle for the drill which gives a bearing support for the drill rod, thus avoids breakage, and which is reversibly mounted so as to increase the range of vertical elevational movement of the drill; furthermore, I have provided a suspendable platform for supporting either one or a pair of machines with booms extended in opposite directions so as to do twice the work that can be done by a single machine within a given time; furthermore, I have provided an easily controllable hydraulic system for effecting numerous additional control movements over conventional control movements to give a degree of flexibility and control not heretofore possible.

In certain applications, such as cleaning soaking pit furnaces or the like, the supporting platform 94 is not necessary, and one or more of the demolition machines can be lowered directly onto the floor of the pit to break up and remove the very hard debris which there accumulates. In this connection, it is considered that the demolition tool can be subsequently replaced with a scooping, scraping or other suitable implement for removing the broken-up de bris. Thus, it will be further apparent that my demolition machine can be utilized for general excavation and grading operations, and the term, demolition, is intended to be inclusive thereof.

While I have shown and described certain presently preferred embodiments of the invention and have illustrated presently preferred methods of practicing the same it is'to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

. I claim:

'1. In a delining apparatus for use in a furnace having an interior brick lining, the combination comprising a platform suspendable within said furnace, means for anchoring said platform to the interior of the furnace at preselected heights, a pair of horizontally disposed turntables spacedly and rotatably mounted on said platform at substantially the same elevational plane, means for rotating said turntables about substantially parallel vertical axes respectively through angles of 360, and extensible boom pivotally mounted on each of said turntables, a demolition tool pivotally mounted on the extensible end of each of said booms, means for pivotally moving said booms through respective vertical arcs, said booms being extendible in opposite directions so that diametrically opposite lining portions may be simultaneously demolished and removed from said furnace around the entire circumference and a substantial height of said lining without changing the location of said platform.

2. In a delining apparatus for use in a furnace having an interior brick lining, the combination comprising a platform for lowering into said furnace, fluid-operated extensible arms extending from the periphery of the platform and engageable with the inner surface of the furnace to anchor the platform at a selected height, a pair of tractors mounted on said platform, each tractor having a horizontally disposed turntable, means for rotating said turntables about parallel vertical axes respectively throughout an angle of 360, an extensible boom mounted on each of said turntables, a drill attached to the end of each of said booms, and means for pivotally moving said booms through respective vertical arcs, the booms of said tractors being extendible in opposite directions so that diametrically opposite lining portions may be simultaneously drilled and removed.

3. The combination recited in claim 2 together with a cradle pivotally mounted at the end of each of said booms for supporting said drill, said cradles each having separate holes angularly displaced therein relative to its pivotal mounting for connection with an operating rod extending from the associated boom, whereby upon removal and reversal of the cradle and reconnection of said operating rod with a different hole, the range of elevational displacement of said cradle relative to said boom is varied.

4. In a delining apparatus for use within a furnace havng an inner brick lining, the combination comprising a platform supported in said furnace, a vehicle including a turntable rotatable about a vertical axis through an angle of 360, a telescoping boom mounted on said turntable and pivotal in a vertical plane, said boom comprising interfitting boom portions of rectangular crosssection, pipes extending along the corners of one of said boom portions, guide rollers rotatably mounted on the other of said boom portions and positioned to roll on said pipes as said boom portions are moved relative to each other, means connected to said boom portions for relatively moving said boom portions between retracted and extended positions thereof, a cradle pivotally mounted on the outer end of one of said boom portions, demolition tool mounted on said cradle, -a drill rod connected to said air hammer, and means for pivotally moving said cradle, whereby the entire circumference and a substantial height of the lining may be removed by said tool.

5. The combination recited in claim 4 characterized in that said pivotally moving means includes an operating rod extending through said telescoping boom portions, said cradle having separate pivot holes an-gularly displaced therein relative to its pivotal connection to said boom for selective connection to said operating rod, whereby when the cradle is removed, reversed and reconnected to said rod at a different pivot hole, a different limit of elevational movement of the cradle relative to the boom is obtained.

6. In a furnace delining apparatus, the combination comprising a chassis including a turntable rotatable about a vertical axis through an angle of 360", a boom pivotally mounted on said turntable, a hydraulically recriprocable operating rod in said boom, hydraulic means connected to said turntable and to said boom for pivoting said boom in a vertical plane, said boom including a base portion of rectangular cross-section and an extensible portion of smaller rectangular cross-section mounted for longitudinal movement therein, roller means including track means within and along the corners of said boom base portion for guiding said extensible portion during movement thereof, means connected to said boom portions for moving said extensible boom portion between extended and wthdrawn positions thereof relative to said base portion, a drill supporting member pivotally mounted on the outward end of said extensible portion and connected to said operating rod for pivotal movement thereby in a vertical plane, and a demolition tool mounted on said supporting member, whereby the entire circumference and a substantial height of said lining may be removed without changing the location of said vehicle.

7. A vehicle for use in delining a furnace and the like, said vehicle comprising a crawler-mounted chassis structure, a turntable rotatably mounted upon said chassis structure and displaceable about a vertical axis through an angle of 360, a boom pivotally mounted on said turntable, hydraulic means connected to said turntable and to said boom for pivoting said boom in a vertical plane, said boom including a base portion of rectangular cross-section and an extensible portion of smaller rectangular cross-section mounted for longitudinal movement therein, roller means including track means within and along the corners of said boom base portion for guiding said extensible portion during movement thereof, means connected to said boom portions for moving said extensible boom portion between extended and withdrawn positions thereof relative to said base portion, a hydraulically reciprocable operating rod in said boom, a demolition tool supporting member pivotally mounted on the outward end of said extensible portion and connected to said operating rod for pivotal movement thereby in a vertical plane, and a demolition tool mounted on said supporting member, whereby the entire circumference and a substantial height of said lining can be removed without changing the location of said vehicle.

8. In a furnace delining apparatus, the combination comprising a chassis including a turntable rotatable about a vertical axis through an angle of 360, a boom pivotally mounted on said turntable, hydraulic means connected to said turntable and to said boom for pivoting said boom in a vertical plane, said boom including a base portion of rectangular cross-section and an extensible portion of smaller rectangular cross-section mounted for longitudinal movement therein, roller means including track means within and along the corners of said boom base portion for guiding said extensible portion during movement thereof, means connected to said boom portions for moving said extensible boom portion between extended and withdrawn positions thereof relative to said base portion, a power actuated demolition tool mounted on the outward end of said extensible portion, and means for actuating said tool for removing said lining.

9. In a delining apparatus for use within a furnace having an inner brick lining, the combination comprising a platform suspendable at preselected locations Within said furnace, a turntable rotatable about a vertical axis through an angle of 360 supported upon said platform, a telescoping boom mounted on said turntable and pivotal in a vertical plane, said boom comprising inter fitting boom portions of rectangular cross-section, rib members extending along the corners of one of said boom portions, guide rollers rotatably mounted on the other of said boom portions and positioned to roll on said rib members as said boom portions are moved relative to one another, a power actuated demolition tool mounted on the outer end of one of said boom portions, and means for actuating said tool for removing said lining.

10. In a delining apparatus for use within a furnace having an inner brick lining, the combination comprising a platform suspendable at preselected locations within said furnace, a turntable rotatable about a vertical axis through an angle of 360 supported upon said platform, a telescoping boom mounted on said turntable and pivotal in a vertical plane, said boom comprising interfitting portions of rectangular cross-section, rib members extending along the corners of one of said boom portions, guide rollers rotatably mounted on the other of said boom portions and positioned to roll on said rib members as said boom portions are moved relative to one another, a power actuated demolition tool pivotally mounted on the outer end of one of said boom portions, said tool pivot mounting being disposed for pivotal movement of said tool through a vertical arc, and means for pivotally moving said tool and for actuating said tool, whereby the entire circumference and a substantial height of said furnace lining can be removed by said tool.

11. In a demolition apparatus, the combination comprising a chassis including a turntable rotatable about a vertical axis through an angle of 360, a boom structure pivotally mounted on said turntable, hydraulic means connected to said turntable and to said boom structure for pivoting said structure in a vertical plane, said boom structure including a base boom portion of given crosssection and an extensible boom portion of complementary cross-section mounted for longitudinal movement thereon, guiding means on said base portion and engaging said extensible portion for guiding said extensible portion during movement thereof relative to said base portion, means connected to said boom portions for moving said extensile portionbetween extended and withdrawn positions thereof relative to said base portion, a power-actuated demolition to-ol mounted on the outward end of said extensible portion, and means for actuating said demolition tool.

12. The combination according to claim 11 wherein said hydraulic means are connected to an end portion of said boom structure opposite from the demolition tool end and to said turntable at a position disposed on the other side to said pivotal mounting relative to the connection of said boom structure.

13. The combination according to claim 11 wherein said demolition tool is mounted on a bracket which is rotatably joined to said extensible boom portion at the outward end thereof, and means are provided for rotating said bracket about the longitudinal axis of said extensible boom portion.

14. The combination according to claim 11 wherein said chassis is crawler mounted, and substantially independent drive means are coupled respectively to the tracks of said crawler.

15. The combination according to claim 11 wherein said boom structure includes a plurality of pivot connections means spaced along the length thereof, each of said pivot connection means being disposed for selective pivotal mounting on said turntable.

16. The combination according to claim 15 wherein means are provided for connecting said hydraulic means to said boom structure at a number of locations spaced along the length thereof, said locations corresponding respectively to said spaced pivotal connection means.

17. The combination according to claim 11 wherein said extensible boom portion is relatively closely fitted within said base boom portion but is spaced therefrom by a plurality of longitudinally extending wearing strips secured to at least one of said boom portions.

18. The combination according to claim 17 wherein said wearing strips extend along substantially the entire length of said extensible boom portion and are secured thereto, and said extensible boom portion is fitted within said base boom portion.

19. In a demolition apparatus for use in a furnace, the combination comprising a platform, means for mounting said platform at a selected position relative to said furnace, a turntable rotatable about a vertical axis through an angle of 360 supported upon said platform, a boom structure pivotally mounted on said turntable, hydraulic means connected to said turntable and to said boom structure for pivoting said structure in a vertical plane, said boom structure including a base boom portion of given cross-section and an extensible boom portion of complementary cross-section mounted for longitudinal movement thereon, guiding means on said base portion and engaging said extensible portion for guiding said extensible portion during movement thereof relative to said base portion, means connected to said boom portions for moving said extensible portion between extended and withdrawn positions thereof relative to said base portion, a power-actuated demolition tool mounted on the outward end of said extensible portion, and means for actuating said demolition tool.

20. A tool cradle for supporting a demolition tool and the like on demolition apparatus having a movable boom assembly, said cradle comprising means for pivotally mounting said cradle adjacent the end of said boom assembly, said cradle having at least two additional pivot means angularly displaced therein relative to said pivot mounting means for selective connection with an operating rod forming part of said boom assembly, whereby upon removal and reversal of the cradle and reconnection of said operating rod with a different one of said additional pivot means the range of elevational displacement of said cradle relative to said boom is varied.

References Cited UNITED STATES PATENTS 2,500,932 3/1950 Curtis et a1.

2,517,980 8/1950 Cornett 29937 2,710,418 6/1955 Putnam 15-10407 2,903,949 9/1959 Simmonds 173-43 2,983,496 5/1961 Grant n 299- X 3,075,754 1/1963 Bles 17344 X 3,090,983 5/1963 Modrak et a1 299-70 X 3,175,239 3/1965 Caspcrson 15104.1

ERNEST R. PURSER, Primqry Examiner. 

11. IN A DEMOLITION APPARATUS, THE COMBINATION COMPRISING A CHASSIS INCLUDING A TURNTABLE ROTATABLE ABOUT A VERTICAL AXIS THROUGH AN ANGLE OF 360*, A BOOM STRUCTURE PIVOTALLY MOUNTED ON SAID TURNTABLE, HYDRAULIC MEANS CONNECTED TO SAID TURNTABLE AND TO SAID BOOM STRUCTURE FOR PIVOTING SAID STRUCTURE IN A VERTICAL PLANE, SAID BOOM STRUCTURE INCLUDING A BASE BOOM PORTION OF GIVEN CROSSSECTION AND AN EXTENSIBLE BOOM PORTION OF COMPLEMENTARY CROSS-SECTIONAL MOUNTED FOR LONGITUDINAL MOVEMENT THEREON, GUIDING MEANS ON SAID BASE PORTION AND ENGAGING SAID EXTENSIBLE PORTION FOR GUIDING SAID EXTENSIBLE PORTION DURING MOVEMENT THEREOF RELATIVE TO SAID BASE PORTION, MEANS CONNECTED TO SAID BOOM PORTIONS FOR MOVING SAID EXTENSIBLE PORTION BETWEEN EXTENDED AND WITHDRAWN POSITIONS THEREOF RELATIVE TO SAID BASE PORTION, A POWER-ACTUATED DEMOLITION TOOL MOUNTED ON THE OUTWARD END OF SAID EXTENSIBLE PORTION, AND MEANS FOR ACTUATING SAID DEMOLITION TOOL. 